runtime/org.argeo.slc.support.simple/src/main/java/org/argeo/slc/jsch/AbstractJschTask.java

   1 package org.argeo.slc.jsch;
   2
   3 import java.io.IOException;
   4 import java.io.InputStream;
   5
   6 import org.apache.commons.logging.Log;
   7 import org.apache.commons.logging.LogFactory;
   8 import org.argeo.slc.SlcException;
   9
  10 import com.jcraft.jsch.JSch;
  11 import com.jcraft.jsch.JSchException;
  12 import com.jcraft.jsch.Session;
  13
  14 public abstract class AbstractJschTask implements Runnable {
  15         private final static Log log = LogFactory.getLog(AbstractJschTask.class);
  16
  17         private SshTarget sshTarget;
  18
  19         protected Session openSession() {
  20                 if (sshTarget.getSession() != null) {
  21                         Session session = sshTarget.getSession();
  22                         if (session.isConnected()) {
  23                                 if (log.isTraceEnabled())
  24                                         log.debug("Using cached session to " + getSshTarget()
  25                                                         + " via SSH");
  26                                 return session;
  27                         }
  28                 }
  29
  30                 try {
  31                         JSch jsch = new JSch();
  32                         if (sshTarget.getUsePrivateKey()
  33                                         && sshTarget.getLocalPrivateKey().exists())
  34                                 jsch.addIdentity(sshTarget.getLocalPrivateKey()
  35                                                 .getAbsolutePath());
  36                         Session session = jsch.getSession(getSshTarget().getUser(),
  37                                         getSshTarget().getHost(), getSshTarget().getPort());
  38
  39                         session.setUserInfo(getSshTarget().getUserInfo());
  40                         session.connect();
  41                         if (log.isDebugEnabled())
  42                                 log.debug("Connected to " + getSshTarget() + " via SSH");
  43                         if (sshTarget.getSession() != null) {
  44                                 if (log.isDebugEnabled())
  45                                         log.debug("The cached session to " + getSshTarget()
  46                                                         + " was disconnected and was reste.");
  47                                 sshTarget.setSession(session);
  48                         }
  49                         return session;
  50                 } catch (JSchException e) {
  51                         throw new SlcException("Could not open session to "
  52                                         + getSshTarget(), e);
  53                 }
  54         }
  55
  56         public final void run() {
  57                 Session session = openSession();
  58                 try {
  59                         run(session);
  60                 } finally {
  61                         if (sshTarget.getSession() == null) {
  62                                 session.disconnect();
  63                                 if (log.isDebugEnabled())
  64                                         log.debug("Disconnected from " + getSshTarget()
  65                                                         + " via SSH");
  66                         }
  67                 }
  68         }
  69
  70         abstract void run(Session session);
  71
  72         protected int checkAck(InputStream in) throws IOException {
  73                 int b = in.read();
  74                 // b may be 0 for success,
  75                 // 1 for error,
  76                 // 2 for fatal error,
  77                 // -1
  78                 if (b == 0)
  79                         return b;
  80                 else if (b == -1)
  81                         return b;// throw new SlcException("SSH ack returned -1");
  82                 else if (b == 1 || b == 2) {
  83                         StringBuffer sb = new StringBuffer();
  84                         int c;
  85                         do {
  86                                 c = in.read();
  87                                 sb.append((char) c);
  88                         } while (c != '\n');
  89                         if (b == 1) { // error
  90                                 throw new SlcException("SSH ack error: " + sb.toString());
  91                         }
  92                         if (b == 2) { // fatal error
  93                                 throw new SlcException("SSH fatal error: " + sb.toString());
  94                         }
  95                 }
  96                 return b;
  97         }
  98
  99         public SshTarget getSshTarget() {
 100                 if (sshTarget == null)
 101                         throw new SlcException("No SSH target defined.");
 102                 return sshTarget;
 103         }
 104
 105         public void setSshTarget(SshTarget sshTarget) {
 106                 this.sshTarget = sshTarget;
 107         }
 108
 109 }